Nathan Fletcher picked up a mayoral endorsement Wednesday from the trade group representing San Diego's life sciences industry, while City Councilman David Alvarez announced that state Assemblywoman Shirley Weber is backing his candidacy.

Representatives of Biocom, a San Diego-based organization representing more than 570 companies in Southern California, said the association decided to back Fletcher after interviewing the three leading candidates seeking to replace former Mayor Bob Filner in a special election Nov. 19. San Diego Councilman Kevin Faulconer is also running for mayor, as is former City Attorney Mike Aguirre, although he wasn't interviewed by Biocom.

"All three of the major candidates shared with us their vision of San Diego. Nathan’s vision was much longer range and had a much higher emphasis on what specifically the life sciences sector does in this economy," said Jimmy Jackson, vice president of public policy for Biocom. "He had a unique understanding of this industry that the other two may or may not have but didn’t vocalize it during our conversations with them."

The trade group also supported Fletcher, now an executive with Qualcomm, when he last ran for mayor in 2012. Faulconer has the backing of a number of business groups, including the San Diego Regional Chamber of Commerce, the local restaurant association and the county Hotel-Motel Association.

Especially appealing to Biocom is Fletcher's recently released jobs plan that places a strong emphasis on growing higher-paying jobs in San Diego's innovation sector. Life science executives also cited the relationships Fletcher has developed over the years with local CEO's.

"He has never hesitated to call CEO's and talk to them about tough issues, and he has a personal relationship with a great number of them," said Magda Marquet, founder of Ajinomoto Althea.

Johnson also cited work Fletcher did shortly after he was elected to the state Assembly in 2008 to push hard for a state tax code revision that would allow companies to have their corporate income taxes based solely on sales within California, a formula designed to reward companies who build facilities and employ individuals in the state. Qualcomm was among a number of California corporations that backed the tax code change.

At an afternoon news conference to highlight Weber's support of Alvarez, the Assemblywoman cited his work on the council to help balance the city’s budget, restore hours to libraries and recreation centers and advance community redevelopment opportunities.

“At the state level, we’re putting ourselves on a path to rebuild California,” Weber said. ”San Diego needs a progressive mayor like Councilmember Alvarez with a vision to rebuild San Diego too, neighborhoods first.”

Elsewhere on the campaign trail, Aguirre called for an audit of the city's Public Utilities Department and urged the council to postpone a Nov. 21 vote to increase water rates until such a review is completed.

"Before we ask the public to again reach into their pockets and accept another round of rate increases," Aguirre said, "we need a proper accounting of what has transpired up to this point."